1
|
Beech JL, Maurya AK, Rodrigues da Silva R, Akpoto E, Asundi A, Fecko JA, Yennawar NH, Sarangi R, Tassone C, Weiss TM, DuBois JL. Understanding the stability of a plastic-degrading Rieske iron oxidoreductase system. Protein Sci 2024; 33:e4997. [PMID: 38723110 PMCID: PMC11081424 DOI: 10.1002/pro.4997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 03/01/2024] [Accepted: 04/06/2024] [Indexed: 05/13/2024]
Abstract
Rieske oxygenases (ROs) are a diverse metalloenzyme class with growing potential in bioconversion and synthetic applications. We postulated that ROs are nonetheless underutilized because they are unstable. Terephthalate dioxygenase (TPADO PDB ID 7Q05) is a structurally characterized heterohexameric α3β3 RO that, with its cognate reductase (TPARED), catalyzes the first intracellular step of bacterial polyethylene terephthalate plastic bioconversion. Here, we showed that the heterologously expressed TPADO/TPARED system exhibits only ~300 total turnovers at its optimal pH and temperature. We investigated the thermal stability of the system and the unfolding pathway of TPADO through a combination of biochemical and biophysical approaches. The system's activity is thermally limited by a melting temperature (Tm) of 39.9°C for the monomeric TPARED, while the independent Tm of TPADO is 50.8°C. Differential scanning calorimetry revealed a two-step thermal decomposition pathway for TPADO with Tm values of 47.6 and 58.0°C (ΔH = 210 and 509 kcal mol-1, respectively) for each step. Temperature-dependent small-angle x-ray scattering and dynamic light scattering both detected heat-induced dissociation of TPADO subunits at 53.8°C, followed by higher-temperature loss of tertiary structure that coincided with protein aggregation. The computed enthalpies of dissociation for the monomer interfaces were most congruent with a decomposition pathway initiated by β-β interface dissociation, a pattern predicted to be widespread in ROs. As a strategy for enhancing TPADO stability, we propose prioritizing the re-engineering of the β subunit interfaces, with subsequent targeted improvements of the subunits.
Collapse
Affiliation(s)
- Jessica Lusty Beech
- Department of Chemistry and BiochemistryMontana State UniversityBozemanMontanaUSA
| | - Anjani K. Maurya
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | | | - Emmanuel Akpoto
- Department of Chemistry and BiochemistryMontana State UniversityBozemanMontanaUSA
| | - Arun Asundi
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Julia Ann Fecko
- The Huck Institutes of the Life SciencesThe Pennsylvania State University, University ParkState CollegePennsylvaniaUSA
| | - Neela H. Yennawar
- The Huck Institutes of the Life SciencesThe Pennsylvania State University, University ParkState CollegePennsylvaniaUSA
| | - Ritimukta Sarangi
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Christopher Tassone
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Thomas M. Weiss
- Stanford Synchrotron Radiation LightsourceSLAC National Accelerator LaboratoryMenlo ParkCaliforniaUSA
| | - Jennifer L. DuBois
- Department of Chemistry and BiochemistryMontana State UniversityBozemanMontanaUSA
| |
Collapse
|
2
|
Truong LN, Wilson Santos E, Zheng YM, Wang YX. Rieske Iron-Sulfur Protein Mediates Pulmonary Hypertension Following Nicotine/Hypoxia Coexposure. Am J Respir Cell Mol Biol 2024; 70:193-202. [PMID: 38029303 PMCID: PMC10914767 DOI: 10.1165/rcmb.2023-0181oc] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 11/29/2023] [Indexed: 12/01/2023] Open
Abstract
The high mortality rate in patients with chronic obstructive pulmonary disease (COPD) may be due to pulmonary hypertension (PH). These diseases are highly associated with cigarette smoke and its key component nicotine. Here, we created a novel animal model of PH using coexposure to nicotine (or cigarette smoke) and hypoxia. This heretofore unreported model showed significant early-onset pulmonary vasoremodeling and PH. Using newly generated mice with complementary smooth muscle-specific Rieske iron-sulfur protein (RISP) gene knockout and overexpression, we demonstrate that RISP is critically involved in promoting pulmonary vasoremodeling and PH, which are implemented by oxidative ataxia telangiectasia-mutated-mediated DNA damage and NF-κB-dependent inflammation in a reciprocal positive mechanism. Together, our findings establish for the first time an animal model of hypoxia-induced early-onset PH in which mitochondrial RISP-dependent DNA damage and NF-κB inflammation play critical roles in vasoremodeling. Specific therapeutic targets for RISP and related oxidative stress-associated signaling pathways may create unique and effective treatments for PH, chronic obstructive pulmonary disease, and their complications.
Collapse
Affiliation(s)
- Lillian N Truong
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Ed Wilson Santos
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Yun-Min Zheng
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Yong-Xiao Wang
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| |
Collapse
|
3
|
Dong Y, Li B, Yin MX, Liu Z, Niu Y, Wu QY, Zhu XL, Yang GF. The Interaction Mechanism of Picolinamide Fungicide Targeting on the Cytochrome bc1 Complex and Its Structural Modification. J Agric Food Chem 2024; 72:3755-3762. [PMID: 38346446 DOI: 10.1021/acs.jafc.3c05982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Picolinamide fungicides, structurally related to UK-2A and antimycin-A, bind into the Qi-site in the bc1 complex. However, the detailed binding mode of picolinamide fungicides remains unknown. In the present study, antimycin-A and UK-2A were selected to study the binding mode of picolinamide inhibitors with four protonation states in the Qi-site by integrating molecular dynamics simulation, molecular docking, and molecular mechanics Generalized Born surface area (MM/GBSA) calculations. Subsequently, a series of new picolinamide derivatives were designed and synthesized to further understand the effects of substituents on the tail phenyl ring. The computational results indicated that the substituted aromatic rings in antimycin-A and UK-2A were the pharmacophore fragments and made the primary contribution when bound to a protein. Compound 9g-hydrolysis formed H-bonds with Hie201 and Ash228 and showed an IC50 value of 6.05 ± 0.24 μM against the porcine bc1 complex. Compound 9c, with a simpler chemical structure, showed higher control effects than florylpicoxamid against cucumber downy mildew and expanded the fungicidal spectrum of picolinamide fungicides. The structural and mechanistic insights obtained from the present study will provide a valuable clue for the future designing of new promising Qi-site inhibitors.
Collapse
Affiliation(s)
- Ying Dong
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Bo Li
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Mao-Xue Yin
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Zheng Liu
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Yan Niu
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Qiong-You Wu
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Xiao-Lei Zhu
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
| | - Guang-Fu Yang
- National Key Laboratory of Green Pesticide, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensor Technology and Health of Ministry of Science and Technology, Central China Normal University, Wuhan 430079, People's Republic of China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300071, People's Republic of China
| |
Collapse
|
4
|
Li Y, Yu J, Li R, Zhou H, Chang X. New insights into the role of mitochondrial metabolic dysregulation and immune infiltration in septic cardiomyopathy by integrated bioinformatics analysis and experimental validation. Cell Mol Biol Lett 2024; 29:21. [PMID: 38291374 PMCID: PMC10826082 DOI: 10.1186/s11658-024-00536-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 01/10/2024] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND Septic cardiomyopathy (SCM), a common cardiovascular comorbidity of sepsis, has emerged among the leading causes of death in patients with sepsis. SCM's pathogenesis is strongly affected by mitochondrial metabolic dysregulation and immune infiltration disorder. However, the specific mechanisms and their intricate interactions in SCM remain unclear. This study employed bioinformatics analysis and drug discovery approaches to identify the regulatory molecules, distinct functions, and underlying interactions of mitochondrial metabolism and immune microenvironment, along with potential interventional strategies in SCM. METHODS GSE79962, GSE171546, and GSE167363 datasets were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and module genes were identified using Limma and Weighted Correlation Network Analysis (WGCNA), followed by functional enrichment analysis. Machine learning algorithms, including support vector machine-recursive feature elimination (SVM-RFE), least absolute shrinkage and selection operator (LASSO) regression, and random forest, were used to screen mitochondria-related hub genes for early diagnosis of SCM. Subsequently, a nomogram was developed based on six hub genes. The immunological landscape was evaluated by single-sample gene set enrichment analysis (ssGSEA). We also explored the expression pattern of hub genes and distribution of mitochondria/inflammation-related pathways in UMAP plots of single-cell dataset. Potential drugs were explored using the Drug Signatures Database (DSigDB). In vivo and in vitro experiments were performed to validate the pathogenetic mechanism of SCM and the therapeutic efficacy of candidate drugs. RESULTS Six hub mitochondria-related DEGs [MitoDEGs; translocase of inner mitochondrial membrane domain-containing 1 (TIMMDC1), mitochondrial ribosomal protein S31 (MRPS31), F-box only protein 7 (FBXO7), phosphatidylglycerophosphate synthase 1 (PGS1), LYR motif containing 7 (LYRM7), and mitochondrial chaperone BCS1 (BCS1L)] were identified. The diagnostic nomogram model based on the six hub genes demonstrated high reliability and validity in both the training and validation sets. The immunological microenvironment differed between SCM and control groups. The Spearman correlation analysis revealed that hub MitoDEGs were significantly associated with the infiltration of immune cells. Upregulated hub genes showed remarkably high expression in the naive/memory B cell, CD14+ monocyte, and plasma cell subgroup, evidenced by the feature plot. The distribution of mitochondria/inflammation-related pathways varied across subgroups among control and SCM individuals. Metformin was predicted to be the most promising drug with the highest combined score. Its efficacy in restoring mitochondrial function and suppressing inflammatory responses has also been validated. CONCLUSIONS This study presents a comprehensive mitochondrial metabolism and immune infiltration landscape in SCM, providing a potential novel direction for the pathogenesis and medical intervention of SCM.
Collapse
Affiliation(s)
- Yukun Li
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
- National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Jiachi Yu
- Department of Cardiology, The Sixth Medical Center of People's Liberation Army General Hospital, Beijing, China
| | - Ruibing Li
- Department of Cardiology, The Sixth Medical Center of People's Liberation Army General Hospital, Beijing, China
| | - Hao Zhou
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
- Department of Cardiology, The Sixth Medical Center of People's Liberation Army General Hospital, Beijing, China.
| | - Xing Chang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
- Guanganmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
| |
Collapse
|
5
|
Rodriguez-Berriguete G, Puliyadi R, Machado N, Barberis A, Prevo R, McLaughlin M, Buffa FM, Harrington KJ, Higgins GS. Antitumour effect of the mitochondrial complex III inhibitor Atovaquone in combination with anti-PD-L1 therapy in mouse cancer models. Cell Death Dis 2024; 15:32. [PMID: 38212297 PMCID: PMC10784292 DOI: 10.1038/s41419-023-06405-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 01/13/2024]
Abstract
Immune checkpoint blockade (ICB) provides effective and durable responses for several tumour types by unleashing an immune response directed against cancer cells. However, a substantial number of patients treated with ICB develop relapse or do not respond, which has been partly attributed to the immune-suppressive effect of tumour hypoxia. We have previously demonstrated that the mitochondrial complex III inhibitor atovaquone alleviates tumour hypoxia both in human xenografts and in cancer patients by decreasing oxygen consumption and consequently increasing oxygen availability in the tumour. Here, we show that atovaquone alleviates hypoxia and synergises with the ICB antibody anti-PD-L1, significantly improving the rates of tumour eradication in the syngeneic CT26 model of colorectal cancer. The synergistic effect between atovaquone and anti-PD-L1 relied on CD8+ T cells, resulted in the establishment of a tumour-specific memory immune response, and was not associated with any toxicity. We also tested atovaquone in combination with anti-PD-L1 in the LLC (lung) and MC38 (colorectal) cancer syngeneic models but, despite causing a considerable reduction in tumour hypoxia, atovaquone did not add any therapeutic benefit to ICB in these models. These results suggest that atovaquone has the potential to improve the outcomes of patients treated with ICB, but predictive biomarkers are required to identify individuals likely to benefit from this intervention.
Collapse
Affiliation(s)
| | - Rathi Puliyadi
- Department of Oncology, University of Oxford, Oxford, UK
| | - Nicole Machado
- Department of Oncology, University of Oxford, Oxford, UK
| | | | - Remko Prevo
- Department of Oncology, University of Oxford, Oxford, UK
| | | | - Francesca M Buffa
- Department of Oncology, University of Oxford, Oxford, UK
- Department of Computing Sciences, Bocconi University, Milan, Italy
| | | | | |
Collapse
|
6
|
Wang Y, Shi Y, Li W, Han X, Lin X, Liu D, Lin Y, Shen L. Knockdown of BRAWNIN minimally affect mitochondrial complex III assembly in human cells. Biochim Biophys Acta Mol Cell Res 2024; 1871:119601. [PMID: 37769950 DOI: 10.1016/j.bbamcr.2023.119601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 10/03/2023]
Abstract
BRAWNIN was found as a mitochondrial respiratory complex III (CIII) assembly factor. Here, we showed that the deletion rather than knockdown of BRAWNIN impaired the assembly of CIII. BRAWNIN levels were affected by nutritional stress and negatively associated with AMPK activation. Although the BRAWNIN knockout via CRISPR/Cas9 led to decreased complex III levels, both biochemical and functional studies of oxidative phosphorylation system (OXPHOS) complexes revealed that knockdown of BRAWNIN neither affected mitochondrial respiration nor impaired the integrity of OXPHOS complexes I-V. Transcriptomic and proteomic profiling further confirmed that the BRAWNIN knockdown had a minimal effect on mitochondrial function. Moreover, only a small proportion of BRAWNIN interacted with the subunits of the OXPHOS complexes, which might be difficult to detect via co-immunoprecipitation and mass spectrometry. Finally, our findings also indicated that although only a minimal amount of BRAWNIN was required for CIII assembly, metabolic analyses revealed that it may fine-tune the pyruvate metabolism route in mitochondria.
Collapse
Affiliation(s)
- Ya Wang
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yu Shi
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Wen Li
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China.; Clinical Laboratory of Central Hospital of Panzhihua City, Panzhihua, Sichuan 617000, China
| | - Xinyu Han
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Xi Lin
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Dandan Liu
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Yuyan Lin
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China
| | - Lijun Shen
- Zhejiang Provincial Key Laboratory of Medical Genetics, Key Laboratory of Laboratory Medicine, Ministry of Education, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325035, China..
| |
Collapse
|
7
|
Abou Haidar L, Harris RC, Pachnis P, Chen H, Gotway GK, Ni M, DeBerardinis RJ. Novel pathogenic UQCRC2 variants in a female with normal neurodevelopment. Cold Spring Harb Mol Case Stud 2023; 9:a006295. [PMID: 37709555 PMCID: PMC10815277 DOI: 10.1101/mcs.a006295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/25/2023] [Indexed: 09/16/2023] Open
Abstract
Electron transport chain (ETC) disorders are a group of rare, multisystem diseases caused by impaired oxidative phosphorylation and energy production. Deficiencies in complex III (CIII), also known as ubiquinol-cytochrome c reductase, are particularly rare in humans. Ubiquinol-cytochrome c reductase core protein 2 (UQCRC2) encodes a subunit of CIII that plays a crucial role in dimerization. Several pathogenic UQCRC2 variants have been identified in patients presenting with metabolic abnormalities that include lactic acidosis, hyperammonemia, hypoglycemia, and organic aciduria. Almost all previously reported UQCRC2-deficient patients exhibited neurodevelopmental involvement, including developmental delays and structural brain anomalies. Here, we describe a girl who presented at 3 yr of age with lactic acidosis, hyperammonemia, and hypoglycemia but has not shown any evidence of neurodevelopmental dysfunction by age 15. Whole-exome sequencing revealed compound heterozygosity for two novel variants in UQCRC2: c.1189G>A; p.Gly397Arg and c.437T>C; p.Phe146Ser. Here, we discuss the patient's clinical presentation and the likely pathogenicity of these two missense variants.
Collapse
Affiliation(s)
- Lea Abou Haidar
- Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Robert C Harris
- Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Panayotis Pachnis
- Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Hongli Chen
- Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Garrett K Gotway
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Eugene McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Min Ni
- Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Ralph J DeBerardinis
- Children's Medical Center Research Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA;
- Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas 75390, USA
- Eugene McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, Texas 75390, USA
| |
Collapse
|
8
|
Wang Y, Yang C, Wang Z, Wang Y, Yan Q, Feng Y, Liu Y, Huang J, Zhou J. Epithelial Galectin-3 Induced the Mitochondrial Complex Inhibition and Cell Cycle Arrest of CD8 + T Cells in Severe/Critical COVID-19. Int J Mol Sci 2023; 24:12780. [PMID: 37628961 PMCID: PMC10454470 DOI: 10.3390/ijms241612780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/20/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
Previous research suggested that the dramatical decrease in CD8+ T cells is a contributing factor in the poor prognosis and disease progression of COVID-19 patients. However, the underlying mechanisms are not fully understood. In this study, we conducted Single-cell RNA sequencing (scRNA-seq) and single-cell T cell receptor sequencing (scTCR-seq) analysis, which revealed a proliferative-exhausted MCM+FASLGlow CD8+ T cell phenotype in severe/critical COVID-19 patients. These CD8+ T cells were characterized by G2/M cell cycle arrest, downregulation of respiratory chain complex genes, and inhibition of mitochondrial biogenesis. CellChat analysis of infected lung epithelial cells and CD8+ T cells found that the galectin signaling pathway played a crucial role in CD8+ T cell reduction and dysfunction. To further elucidate the mechanisms, we established SARS-CoV-2 ORF3a-transfected A549 cells, and co-cultured them with CD8+ T cells for ex vivo experiments. Our results showed that epithelial galectin-3 inhibited the transcription of the mitochondrial respiratory chain complex III/IV genes of CD8+ T cells by suppressing the nuclear translocation of nuclear respiratory factor 1 (NRF1). Further findings showed that the suppression of NRF1 translocation was associated with ERK-related and Akt-related signaling pathways. Importantly, the galectin-3 inhibitor, TD-139, promoted nuclear translocation of NRF1, thus enhancing the expression of the mitochondrial respiratory chain complex III/IV genes and the mitochondrial biogenesis of CD8+ T cells. Our study provided new insights into the immunopathogenesis of COVID-19 and identified potential therapeutic targets for the prevention and treatment of severe/critical COVID-19 patients.
Collapse
Affiliation(s)
- Yudie Wang
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Cheng Yang
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Zhongyi Wang
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Yi Wang
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Qing Yan
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Ying Feng
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Yanping Liu
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Juan Huang
- Department of Hematology, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430070, China
| | - Jingjiao Zhou
- Department of Biology and Genetics, College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan 430065, China
| |
Collapse
|
9
|
Flores-Mireles D, Camacho-Villasana Y, Lutikurti M, García-Guerrero AE, Lozano-Rosas G, Chagoya V, Gutiérrez-Cirlos EB, Brandt U, Cabrera-Orefice A, Pérez-Martínez X. The cytochrome b carboxyl terminal region is necessary for mitochondrial complex III assembly. Life Sci Alliance 2023; 6:e202201858. [PMID: 37094942 PMCID: PMC10132202 DOI: 10.26508/lsa.202201858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 04/09/2023] [Accepted: 04/11/2023] [Indexed: 04/26/2023] Open
Abstract
Mitochondrial bc 1 complex from yeast has 10 subunits, but only cytochrome b (Cytb) subunit is encoded in the mitochondrial genome. Cytb has eight transmembrane helices containing two hemes b for electron transfer. Cbp3 and Cbp6 assist Cytb synthesis, and together with Cbp4 induce Cytb hemylation. Subunits Qcr7/Qcr8 participate in the first steps of assembly, and lack of Qcr7 reduces Cytb synthesis through an assembly-feedback mechanism involving Cbp3/Cbp6. Because Qcr7 resides near the Cytb carboxyl region, we wondered whether this region is important for Cytb synthesis/assembly. Although deletion of the Cytb C-region did not abrogate Cytb synthesis, the assembly-feedback regulation was lost, so Cytb synthesis was normal even if Qcr7 was missing. Mutants lacking the Cytb C-terminus were non-respiratory because of the absence of fully assembled bc 1 complex. By performing complexome profiling, we showed the existence of aberrant early-stage subassemblies in the mutant. In this work, we demonstrate that the C-terminal region of Cytb is critical for regulation of Cytb synthesis and bc 1 complex assembly.
Collapse
Affiliation(s)
- Daniel Flores-Mireles
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | - Yolanda Camacho-Villasana
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | - Madhurya Lutikurti
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Aldo E García-Guerrero
- Department of Medicine and Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Guadalupe Lozano-Rosas
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | - Victoria Chagoya
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| | | | - Ulrich Brandt
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alfredo Cabrera-Orefice
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Xochitl Pérez-Martínez
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, México
| |
Collapse
|
10
|
Hayward JA, Makota FV, Cihalova D, Leonard RA, Rajendran E, Zwahlen SM, Shuttleworth L, Wiedemann U, Spry C, Saliba KJ, Maier AG, van Dooren GG. A screen of drug-like molecules identifies chemically diverse electron transport chain inhibitors in apicomplexan parasites. PLoS Pathog 2023; 19:e1011517. [PMID: 37471441 PMCID: PMC10403144 DOI: 10.1371/journal.ppat.1011517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/04/2023] [Accepted: 06/28/2023] [Indexed: 07/22/2023] Open
Abstract
Apicomplexans are widespread parasites of humans and other animals, and include the causative agents of malaria (Plasmodium species) and toxoplasmosis (Toxoplasma gondii). Existing anti-apicomplexan therapies are beset with issues around drug resistance and toxicity, and new treatment options are needed. The mitochondrial electron transport chain (ETC) is one of the few processes that has been validated as a drug target in apicomplexans. To identify new inhibitors of the apicomplexan ETC, we developed a Seahorse XFe96 flux analyzer approach to screen the 400 compounds contained within the Medicines for Malaria Venture 'Pathogen Box' for ETC inhibition. We identified six chemically diverse, on-target inhibitors of the ETC in T. gondii, at least four of which also target the ETC of Plasmodium falciparum. Two of the identified compounds (MMV024937 and MMV688853) represent novel ETC inhibitor chemotypes. MMV688853 belongs to a compound class, the aminopyrazole carboxamides, that were shown previously to target a kinase with a key role in parasite invasion of host cells. Our data therefore reveal that MMV688853 has dual targets in apicomplexans. We further developed our approach to pinpoint the molecular targets of these inhibitors, demonstrating that all target Complex III of the ETC, with MMV688853 targeting the ubiquinone reduction (Qi) site of the complex. Most of the compounds we identified remain effective inhibitors of parasites that are resistant to Complex III inhibitors that are in clinical use or development, indicating that they could be used in treating drug resistant parasites. In sum, we have developed a versatile, scalable approach to screen for compounds that target the ETC in apicomplexan parasites, and used this to identify and characterize novel inhibitors.
Collapse
Affiliation(s)
- Jenni A. Hayward
- Research School of Biology, Australian National University, Canberra, Australia
| | - F. Victor Makota
- Research School of Biology, Australian National University, Canberra, Australia
| | - Daniela Cihalova
- Research School of Biology, Australian National University, Canberra, Australia
| | - Rachel A. Leonard
- Research School of Biology, Australian National University, Canberra, Australia
| | - Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australia
| | - Soraya M. Zwahlen
- Research School of Biology, Australian National University, Canberra, Australia
| | - Laura Shuttleworth
- Research School of Biology, Australian National University, Canberra, Australia
| | - Ursula Wiedemann
- Research School of Biology, Australian National University, Canberra, Australia
| | - Christina Spry
- Research School of Biology, Australian National University, Canberra, Australia
| | - Kevin J. Saliba
- Research School of Biology, Australian National University, Canberra, Australia
| | - Alexander G. Maier
- Research School of Biology, Australian National University, Canberra, Australia
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, Australia
| |
Collapse
|
11
|
Rosell-Hidalgo A, Moore AL, Ghafourian T. Prediction of drug-induced mitochondrial dysfunction using succinate-cytochrome c reductase activity, QSAR and molecular docking. Toxicology 2023; 485:153412. [PMID: 36584908 DOI: 10.1016/j.tox.2022.153412] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/15/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
There is increasing evidence that links mitochondrial off-target effects with organ toxicities. For this reason, predictive strategies need to be developed to identify mitochondrial dysfunction early in the drug discovery process. In this study, as a major mechanism of mitochondrial toxicity, first, the inhibitory activity of 35 compounds against succinate-cytochrome c reductase (SCR) was investigated. This in vitro study led to the generation of consistent experimental data for a diverse range of compounds, including pharmaceutical drugs and fungicides. Next, molecular docking and protein-ligand interaction fingerprinting (PLIF) analysis were used to identify significant residues and protein-ligand interactions for the Qo site of complex III and Q site of complex II. Finally, this data was used for the development of QSAR models using a regression-based approach to highlight structural and chemical features that might be responsible for SCR inhibition. The statistically validated QSAR models from this work highlighted the importance of low aqueous solubility, low ionisation, fewer 6-membered rings and shorter hydrocarbon alkane chains in the molecular structure for increased inhibition of SCR, hence mitochondrial toxicity. PLIF analysis highlighted two key residues for inhibitory activity of the Qo site of complex III: His 161 as H-bond acceptor and Pro 270 for arene interactions. Currently, there are limited structure-activity models published in the scientific literature for the prediction of mitochondrial toxicity. We believe this study helps shed light on the chemical space for the inhibition of mitochondrial electron transport chain (ETC).
Collapse
Affiliation(s)
- Alicia Rosell-Hidalgo
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, United Kingdom.
| | - Anthony L Moore
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, United Kingdom
| | - Taravat Ghafourian
- NSU College of Pharmacy, 3200 South University Drive, Ft. Lauderdale, FL 33328-2018, USA.
| |
Collapse
|
12
|
Luo B, Ning Y, Rao B. Comprehensive Overview of β-Methoxyacrylate Derivatives as Cytochrome bc1 Inhibitors for Novel Pesticide Discovery. J Agric Food Chem 2022; 70:15615-15630. [PMID: 36480156 DOI: 10.1021/acs.jafc.2c04820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
β-Methoxyacrylate derivatives represent a new class of pesticides, which have attracted increasing attention owing to their unique structure, broad biological activity, and unique mechanisms of action. They inhibit mitochondrial respiration via preventing electron transfer at the Qo site of the cytochrome bc1 complex and thus are identified as cyt bc1 inhibitors. A variety of β-methoxyacrylate derivatives have been reported by many research groups for discovery of novel pesticides with improved expected activities. This review focuses on development of β-methoxyacrylate derivatives with great significance as pesticides such as fungicides, acaricides, insecticides, herbicides, and antiviral agents. In addition, the structure-activity relationships (SARs) of β-methoxyacrylate derivatives are summarized. Moreover, the cause of resistance to β-methoxyacrylate fungicides and some solutions are also introduced. Finally, the development trend of β-methoxyacrylate derivatives as pesticides is explored. We hope the review will give a guide to develop novel β-methoxyacrylate pesticides in the future.
Collapse
Affiliation(s)
- Bo Luo
- College of Life Sciences, Tea Plant Biology Key Laboratory of Henan Province, Xinyang Normal University, Xinyang 464000, China
| | - Yuli Ning
- College of Life Sciences, Tea Plant Biology Key Laboratory of Henan Province, Xinyang Normal University, Xinyang 464000, China
| | - Benqiang Rao
- College of Life Sciences, Tea Plant Biology Key Laboratory of Henan Province, Xinyang Normal University, Xinyang 464000, China
| |
Collapse
|
13
|
Kildea S, Hellin P, Heick TM, Hutton F. Baseline sensitivity of European Zymoseptoria tritici populations to the complex III respiration inhibitor fenpicoxamid. Pest Manag Sci 2022; 78:4488-4496. [PMID: 35797347 PMCID: PMC9796354 DOI: 10.1002/ps.7067] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Fenpicoxamid is a recently developed fungicide belonging to the quinone inside inhibitor (QiI) group. This is the first fungicide within this group to be active against the Zymoseptoria tritici, which causes Septoria tritici blotch on wheat. The occurrence of pre-existing resistance mechanisms was monitored, using sensitivity assays and Illumina sequencing, in Z. tritici populations sampled in multiple European countries before the introduction of fenpicoxamid. RESULTS Although differences in sensitivity to all three fungicides tested (fenpicoxamid, fentin chloride and pyraclostrobin) existed between the isolate collections, no alterations associated with QiI resistance were detected. Among the isolates, a range in sensitivity to fenpicoxamid was observed (ratio between most sensitive/least sensitive = 53.1), with differences between the most extreme isolates when tested in planta following limited fenpicoxamid treatment. Sensitivity assays using fentin chloride suggest some of the observed differences in fenpicoxamid sensitivity are associated with multi-drug resistance. Detailed monitoring of the wider European population using Illumina-based partial sequencing of the Z. tritici also only detected the presence of G143A, with differences in frequencies of this alteration observed across the region. CONCLUSIONS This study provides a baseline sensitivity for European Z. tritici populations to fenpicoxamid. Target-site resistance appears to be limited or non-existing in European Z. tritici populations prior to the introduction of fenpicoxamid. Non-target site resistance mechanisms exist, but their impact in the field is predicted to be limited. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Steven Kildea
- Teagasc, The Agriculture and Food Development AuthorityCarlowIreland
| | - Pierre Hellin
- Plant and Forest Health Unit, Walloon Agricultural Research CenterGemblouxBelgium
| | - Thies M. Heick
- Department of AgroecologyAarhus UniversitySlagelseDenmark
| | - Fiona Hutton
- Teagasc, The Agriculture and Food Development AuthorityCarlowIreland
| |
Collapse
|
14
|
Liu X, Tang D, Yin F, Wang J, Zhang X, Xiao Y, Li JQ, Qin Z. Mitochondrion-Targeted Triphenylphosphonium-Based Kresoxim-Methyl Analogues: Synthesis, Fungicidal Activity, and Action Mechanism Approach. J Agric Food Chem 2022; 70:13563-13573. [PMID: 36223487 DOI: 10.1021/acs.jafc.2c05071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
β-Methoxyacrylate fungicides as complex III Qo site inhibitors play a crucial role in the control of crop diseases. In this study, the triphenylphosphonium (TPP)-driven mitochondrion-targeting strategy was used to modify the kresoxim-methyl scaffold at the toxicophore or side chain to develop novel mitochondrion-targeted QoI fungicides. These kresoxim-methyl analogues exhibited different fungicidal activities, depending on the position of TPP conjugation and the linker length. Among them, 2A-5 and 2C-4 showed excellent characteristics superior to kresoxim-methyl as candidate fungicides, in which the activity enhancement against Phytophthora capsici was the most remarkable, with an EC50 value of about 5 μM. Notably, both hyphal and zoospore structures of the pathogens were severely damaged after treatment with them. The action mechanism approach revealed that they might cause a significant decrease in ATP synthesis and ROS outbreak in different ways. The results also provided a new insight into the contribution of targeting group TPP to the fungicidal activity in TPP-driven fungicides.
Collapse
Affiliation(s)
- Xuelian Liu
- College of Science, China Agricultural University, Beijing100193, China
| | - Dachao Tang
- College of Science, China Agricultural University, Beijing100193, China
| | - Fahong Yin
- College of Science, China Agricultural University, Beijing100193, China
| | - Jiayao Wang
- College of Science, China Agricultural University, Beijing100193, China
| | - Xueqin Zhang
- College of Biological Sciences, China Agricultural University, Beijing100193, China
| | - Yumei Xiao
- College of Science, China Agricultural University, Beijing100193, China
| | - Jia-Qi Li
- College of Science, China Agricultural University, Beijing100193, China
| | - Zhaohai Qin
- College of Science, China Agricultural University, Beijing100193, China
| |
Collapse
|
15
|
Bashir S, Houf W, Liu JL, Mulvaney SP. 3D Conducting Polymeric Membrane and Scaffold Saccharomyces cerevisiae Biofilms to Enhance Energy Conversion in Microbial Fuel Cells. ACS Appl Mater Interfaces 2022; 14:20393-20403. [PMID: 34962123 DOI: 10.1021/acsami.1c20445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Microbial fuel cells (MFCs) can spontaneously convert chemical energy into electricity using biocatalytic microorganisms and organic matter as fuel feedstocks. Three-dimensional cross-linked poly(vinyl alcohol)-based membranes were produced by a sol-gel method under homogeneous catalysis and used as the electrolyte to facilitate effective proton conduction. Under dry conditions, these polymeric membranes showed high water uptake (120%) and ionic conductivity (2.815 mS cm-1). In the anode compartment, the scaffold Saccharomyces cerevisiae film biocatalysts were used to improve electron transfer to the cathode, using three major configurations to generate a higher power output. It was found that the graphene anchoring, red light (RL) stimulation, and methylene blue (MB) mediation-enhanced device performance. The electrochemically derived graphene improved the power and current density by 40% because of its high conductivity. The RL stimulation increased the power density by 80% because of a shortened electron flow path to complex III. The MB mediation also yielded a higher current density by 340% because MB can bypass the electron flow from complex II to cytochrome c and transfer electrons directly to complex III. The individual and collective increase in power output was due to more efficient electron flow from the electronic network permeating the biofilm. The generated electrons were transferred either to graphene as an energy-efficient direct transfer mode or to methylene blue as a long-range redox mediator for indirect transfer. Red light stimulation enhanced oxygen utilization efficiency and stimulated electrons in redox proteins enhancing electron flux. These processes generated higher power through the more efficient generation of electrons and faster transport to the external circuit. As society migrates from gasoline consumption to low carbon-based fuels, the MFCs become important in producing electrical energy with low net emissions.
Collapse
Affiliation(s)
- Sajid Bashir
- Department of Chemistry, Texas A&M University-Kingsville, 700 University Boulevard, MSC 161, Kingsville, Texas 78363-8202, United States
| | - William Houf
- Department of Chemistry, Texas A&M University-Kingsville, 700 University Boulevard, MSC 161, Kingsville, Texas 78363-8202, United States
| | - Jingbo L Liu
- Department of Chemistry, Texas A&M University-Kingsville, 700 University Boulevard, MSC 161, Kingsville, Texas 78363-8202, United States
- Texas A&M Energy Institute, Frederick E. Giesecke Engineering Research Building, 3372 TAMU, College Station, Texas 77843-3372, United States
| | - Shawn P Mulvaney
- Chemistry Division, U.S. Naval Research Laboratory, 4555 Overlook Avenue Southwest, Washington, DC 20375-5342, United States
| |
Collapse
|
16
|
Cadenas E. Commentary on "Production of superoxide radicals and hydrogen peroxide by NADH-ubiquinone reductase and ubiquinol-cytochrome c reductase from beef-heart mitochondria". Arch Biochem Biophys 2022; 726:109214. [PMID: 35483432 DOI: 10.1016/j.abb.2022.109214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
On Production of superoxide radicals and hydrogen peroxide by NADH-ubiquinone reductase and ubiquinol-cytochrome c reductase from beef-heart mitochondria (Arch Biochem Biophys (1977) 180, 248-257) reviews early work that influenced future studies on the mitochondrial production of superoxide anion and hydrogen peroxide.
Collapse
Affiliation(s)
- Enrique Cadenas
- Pharmacology & Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, 90089, USA.
| |
Collapse
|
17
|
Vidali S, Gerlini R, Thompson K, Urquhart JE, Meisterknecht J, Aguilar‐Pimentel JA, Amarie OV, Becker L, Breen C, Calzada‐Wack J, Chhabra NF, Cho Y, da Silva‐Buttkus P, Feichtinger RG, Gampe K, Garrett L, Hoefig KP, Hölter SM, Jameson E, Klein‐Rodewald T, Leuchtenberger S, Marschall S, Mayer‐Kuckuk P, Miller G, Oestereicher MA, Pfannes K, Rathkolb B, Rozman J, Sanders C, Spielmann N, Stoeger C, Szibor M, Treise I, Walter JH, Wurst W, Mayr JA, Fuchs H, Gärtner U, Wittig I, Taylor RW, Newman WG, Prokisch H, Gailus‐Durner V, Hrabě de Angelis M. Characterising a homozygous two-exon deletion in UQCRH: comparing human and mouse phenotypes. EMBO Mol Med 2021; 13:e14397. [PMID: 34750991 PMCID: PMC8649870 DOI: 10.15252/emmm.202114397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial disorders are clinically and genetically diverse, with isolated complex III (CIII) deficiency being relatively rare. Here, we describe two affected cousins, presenting with recurrent episodes of severe lactic acidosis, hyperammonaemia, hypoglycaemia and encephalopathy. Genetic investigations in both cases identified a homozygous deletion of exons 2 and 3 of UQCRH, which encodes a structural complex III (CIII) subunit. We generated a mouse model with the equivalent homozygous Uqcrh deletion (Uqcrh-/- ), which also presented with lactic acidosis and hyperammonaemia, but had a more severe, non-episodic phenotype, resulting in failure to thrive and early death. The biochemical phenotypes observed in patient and Uqcrh-/- mouse tissues were remarkably similar, displaying impaired CIII activity, decreased molecular weight of fully assembled holoenzyme and an increase of an unexpected large supercomplex (SXL ), comprising mostly of one complex I (CI) dimer and one CIII dimer. This phenotypic similarity along with lentiviral rescue experiments in patient fibroblasts verifies the pathogenicity of the shared genetic defect, demonstrating that the Uqcrh-/- mouse is a valuable model for future studies of human CIII deficiency.
Collapse
|
18
|
Abstract
Atomic structures of mitochondrial enzyme complexes in plants are shedding light on their multiple functions.
Collapse
Affiliation(s)
- Hans-Peter Braun
- Institut für Pflanzengenetik, Leibniz Universität HannoverHannoverGermany
| |
Collapse
|
19
|
Li Y, Ivica NA, Dong T, Papageorgiou DP, He Y, Brown DR, Kleyman M, Hu G, Chen WW, Sullivan LB, Del Rosario A, Hammond PT, Vander Heiden MG, Chen J. MFSD7C switches mitochondrial ATP synthesis to thermogenesis in response to heme. Nat Commun 2020; 11:4837. [PMID: 32973183 PMCID: PMC7515921 DOI: 10.1038/s41467-020-18607-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 08/31/2020] [Indexed: 12/18/2022] Open
Abstract
ATP synthesis and thermogenesis are two critical outputs of mitochondrial respiration. How these outputs are regulated to balance the cellular requirement for energy and heat is largely unknown. Here we show that major facilitator superfamily domain containing 7C (MFSD7C) uncouples mitochondrial respiration to switch ATP synthesis to thermogenesis in response to heme. When heme levels are low, MSFD7C promotes ATP synthesis by interacting with components of the electron transport chain (ETC) complexes III, IV, and V, and destabilizing sarcoendoplasmic reticulum Ca2+-ATPase 2b (SERCA2b). Upon heme binding to the N-terminal domain, MFSD7C dissociates from ETC components and SERCA2b, resulting in SERCA2b stabilization and thermogenesis. The heme-regulated switch between ATP synthesis and thermogenesis enables cells to match outputs of mitochondrial respiration to their metabolic state and nutrient supply, and represents a cell intrinsic mechanism to regulate mitochondrial energy metabolism.
Collapse
Affiliation(s)
- Yingzhong Li
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Nikola A Ivica
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ting Dong
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Dimitrios P Papageorgiou
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Yanpu He
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Douglas R Brown
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Marianna Kleyman
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Guangan Hu
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Walter W Chen
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Boston Combined Residency Program, Department of Pediatrics, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Lucas B Sullivan
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Amanda Del Rosario
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Paula T Hammond
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Jianzhu Chen
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| |
Collapse
|
20
|
Thiriveedi VR, Mattam U, Pattabhi P, Bisoyi V, Talari NK, Krishnamoorthy T, Sepuri NBV. Glutathionylated and Fe-S cluster containing hMIA40 (CHCHD4) regulates ROS and mitochondrial complex III and IV activities of the electron transport chain. Redox Biol 2020; 37:101725. [PMID: 32971361 PMCID: PMC7511737 DOI: 10.1016/j.redox.2020.101725] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/02/2020] [Accepted: 09/11/2020] [Indexed: 12/14/2022] Open
Abstract
Human MIA40, an intermembrane space (IMS) import receptor of mitochondria harbors twin CX9C motifs for stability while its CPC motif is known to facilitate the import of IMS bound proteins. Site-directed mutagenesis complemented by MALDI on in vivo hMIA40 protein shows that a portion of MIA40 undergoes reversible S-glutathionylation at three cysteines in the twin CX9C motifs and the lone cysteine 4 residue. We find that HEK293T cells expressing hMIA40 mutant defective for glutathionylation are compromised in the activities of complexes III and IV of the Electron Transport Chain (ETC) and enhance Reactive Oxygen Species (ROS) levels. Immunocapture studies show MIA40 interacting with complex III. Interestingly, glutathionylated MIA40 can transfer electrons to cytochrome C directly. However, Fe–S clusters associated with the CPC motif are essential to facilitate the two-electron to one-electron transfer for reducing cytochrome C. These results suggest that hMIA40 undergoes glutathionylation to maintain ROS levels and for optimum function of complexes III and IV of ETC. Our studies shed light on a novel post-translational modification of hMIA40 and its ability to act as a redox switch to regulate the ETC and cellular redox homeostasis.
Collapse
Affiliation(s)
| | - Ushodaya Mattam
- Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad, TS, 500046, India
| | - Prasad Pattabhi
- Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad, TS, 500046, India
| | - Vandana Bisoyi
- Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad, TS, 500046, India
| | - Noble Kumar Talari
- Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad, TS, 500046, India
| | - Thanuja Krishnamoorthy
- Vectrogen Biologicals Pvt.Ltd., BioNEST, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, TS, 500046, India
| | - Naresh Babu V Sepuri
- Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad, TS, 500046, India.
| |
Collapse
|
21
|
Borek A, Ekiert R, Osyczka A. [Molecular effects of mitochondrial mutations in cytochrome b of complex III and their impact on the levels of free radical production]. Postepy Biochem 2016; 62:162-172. [PMID: 28132468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 05/23/2016] [Indexed: 06/06/2023]
Abstract
Cytochrome bc1 (mitochondrial complex III) is a common element of several bioenergetic systems. This enzyme catalyses electron transfer from ubiquinol to cytochrome c coupled to translocation of protons across the membrane, which contributes to generation of protonmotive force utilized for ATP production. Cytochrome b, together with cytochrome c1 and iron-sulfur protein (ISP), forms the evolutionarily conserved catalytic core. Transfer of electrons within this enzyme, is facilitated by the movement of ISP domain that allows communication between cytochrome b and cytochrome c1. Mutations in the subunits of catalytic core may cause mitochondrial diseases, however elucidation of their molecular effects in human cells is difficult. For that reason yeast or bacterial systems are used. It was found that some mutations in cytochrome b influence the movement of ISP and, in consequence, the levels of superoxide generation. By exploring the effects of mitochondrial mutations in model systems one can not only learn about molecular basis of diseases but also gain insights about catalytic and side reactions in cytochrome bc1.
Collapse
Affiliation(s)
- Arkadiusz Borek
- Department of Molecular Biophysics; Faculty of Biochemistry, Biophysics and Biotechnology; Jagiellonian University; 7 Gronostajowa St., 30-387 Kraków, Poland
| | - Robert Ekiert
- Department of Molecular Biophysics; Faculty of Biochemistry, Biophysics and Biotechnology; Jagiellonian University; 7 Gronostajowa St., 30-387 Kraków, Poland
| | - Artur Osyczka
- Department of Molecular Biophysics; Faculty of Biochemistry, Biophysics and Biotechnology; Jagiellonian University; 7 Gronostajowa St., 30-387 Kraków, Poland
| |
Collapse
|
22
|
Liguori R, Mazzaccara C, Pasanisi F, Buono P, Oriani G, Finelli C, Contaldo F, Sacchetti L. The mtDNA 15497 G/A polymorphism in cytochrome b in severe obese subjects from Southern Italy. Nutr Metab Cardiovasc Dis 2006; 16:466-470. [PMID: 17015183 DOI: 10.1016/j.numecd.2005.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 06/14/2005] [Accepted: 06/23/2005] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIM A large number of mitochondrial DNA (mtDNA) mutations have been implicated in degenerative diseases and aging. The aim of this study was to evaluate whether the 15497 G/A mtDNA polymorphism (G251S) in the cytochrome b subunit of respiratory complex III, which has been associated with obesity-related variables and lipid metabolism in a Japanese population, is associated with severe obesity also in adult Caucasians from southern Italy. METHODS AND RESULTS Unrelated severely obese patients (n = 317; BMI > 40kg/m2) and controls (n = 217; BMI < 25kg/m2) from Southern Italy were genotyped by allelic discrimination TaqMan assay for the 15497 G/A mtDNA polymorphism. In obese patients fasting serum total cholesterol, triglycerides, HDL-cholesterol and glucose were measured enzymatically and sitting blood pressure and heart rate were also collected. Mean levels of total cholesterol, triglycerides and glucose were below the upper reference limit for healthy subjects. Female obese subjects showed lower levels of blood pressure and heart rate and higher levels of HDL cholesterol than male obese patients (P < 0.001). All the control subjects and 315/317 severely obese patients were homozygous for the G allele (wild type), whereas only 2/317, were females homozygous for the A allele. CONCLUSIONS The mtDNA 15497 G/A polymorphism in cytochrome b was present in 0.6% obese subjects, two females whose lipid parameters and BMI were similar to those of the overall group. Therefore, this mutation may appear to contribute in rare instances to severe obesity but does not explain the majority of cases in our population. A more extensive genetic haplogroup characterization is required to identify associations to obesity in Caucasians.
Collapse
Affiliation(s)
- Rosario Liguori
- Department of Biochemistry and Medical Biotechnology, University Naples Federico II, Via Pansini 5, 80131 Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Eubel H, Heinemeyer J, Sunderhaus S, Braun HP. Respiratory chain supercomplexes in plant mitochondria. Plant Physiol Biochem 2004; 42:937-42. [PMID: 15707832 DOI: 10.1016/j.plaphy.2004.09.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Accepted: 09/24/2004] [Indexed: 05/23/2023]
Abstract
Supercomplexes are defined associations of protein complexes, which are important for several cellular functions. This "quintenary" organization level of protein structure recently was also described for the respiratory chain of plant mitochondria. Except succinate dehydrogenase (complex II), all complexes of the oxidative phosphorylation (OXPOS) system (complexes I, III, IV and V) were found to form part of supercomplexes. Compositions of these supramolecular structures were systematically investigated using digitonin solubilizations of mitochondrial fractions and two-dimensional Blue-native (BN) polyacrylamide gel electrophoresis. The most abundant supercomplex of plant mitochondria includes complexes I and III at a 1:2 ratio (I1 + III2 supercomplex). Furthermore, some supercomplexes of lower abundance could be described, which have I2 + III4, V2, III2 + IV(1-2), and I1 + III2 + IV(1-4) compositions. Supercomplexes consisting of complexes I plus III plus IV were proposed to be called "respirasome", because they autonomously can carry out respiration in the presence of ubiquinone and cytochrome c. Plant specific alternative oxidoreductases of the respiratory chain were not associated with supercomplexes under all experimental conditions tested. However, formation of supercomplexes possibly indirectly regulates alternative respiratory pathways in plant mitochondria on the basis of electron channeling. In this review, procedures to characterize the supermolecular organization of the plant respiratory chain and results concerning supercomplex structure and function are summarized and discussed.
Collapse
Affiliation(s)
- Holger Eubel
- Institut für Angewandte Genetik, Universität Hannover, Herrenhäuser Street 2, 30419 Hannover, Germany
| | | | | | | |
Collapse
|
24
|
Camacho A, Moreno-Sanchez R, Bernal-Lugo I. Control of superoxide production in mitochondria from maize mesocotyls. FEBS Lett 2004; 570:52-6. [PMID: 15251438 DOI: 10.1016/j.febslet.2004.06.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 05/26/2004] [Accepted: 06/10/2004] [Indexed: 10/26/2022]
Abstract
To understand the biochemical events that control the generation of superoxide, the effect of inhibiting the respiratory complexes III and IV (C-III and C-IV) and alternative oxidase (AOX) on the rate of superoxide production was analyzed in mitochondria from maize seedlings. To increase superoxide production, it was required to inhibit C-III or C-IV by at least 30% or 50%, respectively. Below this inhibition threshold, AOX exerted the highest degree of control on superoxide production, whereas above it, the highest degree of control was exerted by C-IV. The contribution of C-III to control superoxide production became significant when AOX activity was modulated.
Collapse
Affiliation(s)
- Adriana Camacho
- Departamento de Bioquímica, Facultad de Química, UNAM, 04510 Mexico D.F.
| | | | | |
Collapse
|
25
|
Abstract
Comprehensive phylogenetic analysis of the subunits of respiratory chain was carried out using a variety of mitochondrial and bacterial sequences including those from all unfinished alpha-proteobacterial genomes known to date. Maximum likelihood, neighbor-joining, and maximum parsimony consensus trees, based on four proton-translocating complexes, placed mitochondria as a sister group to the order Rickettsiales of obligate endosymbiotic bacteria to the exclusion of free-living alpha-proteobacteria. Thus, phylogenetic relationship of most eukaryotic respiratory enzymes conforms to canonical pattern of mitochondrial ancestry, prior established in analyses of ribosomal RNAs, which are encoded by residual mitochondrial genomes. These data suggest that mitochondria may have derived from a reduced intracellular bacterium and that respiration may be the only evolutionary novelty brought into eukaryotes by mitochondrial endosymbiont.
Collapse
Affiliation(s)
- Victor V Emelyanov
- Department of General Microbiology, Gamaleya Institute of Epidemiology and Microbiology, Gamaleya Street 18, Moscow 123098, Russia.
| |
Collapse
|
26
|
Modena P, Testi MA, Facchinetti F, Mezzanzanica D, Radice MT, Pilotti S, Sozzi G. UQCRH gene encoding mitochondrial Hinge protein is interrupted by a translocation in a soft-tissue sarcoma and epigenetically inactivated in some cancer cell lines. Oncogene 2003; 22:4586-93. [PMID: 12881716 DOI: 10.1038/sj.onc.1206472] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We previously reported the identification of a novel zinc-finger gene, designated ZSG, fused to Ewing sarcoma gene (EWS) by a submicroscopic paracentric inversion of 22q12 in a small round cell sarcoma presenting a translocation t(1;22)(p34;q12). We report here the molecular cloning and characterization of the breakpoint in 1p34, which encompasses the gene coding for mitochondrial Hinge protein ubiquinol-cytochrome C reductase hinge gene (UQCRH). All the three breakpoints, two on 22q12 and one in 1p34, interrupt different genes: EWS, ZSG and UQCRH. We determined the genomic structure of UQCRH, characterized its splicing variants and identified a transcribed processed pseudogene. The analysis of UQCRH expression in normal tissues and cancer cell lines revealed absent expression of UQCRH in two ovarian and one breast cancer cell lines and reduced expression in a further breast carcinoma cell line. CpG island methylation upstream exon 1 was detected in all the three cell lines with absent expression. Moreover, treatment with demethylating agent 5-azacytidine restored UQCRH expression in OAW42 ovarian cancer cells. These data provide preliminary evidence of the inactivation of UQCRH gene in cancer either by structural rearrangements or epigenetic mechanisms.
Collapse
Affiliation(s)
- Piergiorgio Modena
- Unit of Molecular Cytogenetics, Istituto Nazionale Tumori, via G. Venezian 1, 20133 Milano, Italy
| | | | | | | | | | | | | |
Collapse
|
27
|
Hunsicker-Wang LM, Heine A, Chen Y, Luna EP, Todaro T, Zhang YM, Williams PA, McRee DE, Hirst J, Stout CD, Fee JA. High-resolution structure of the soluble, respiratory-type Rieske protein from Thermus thermophilus: analysis and comparison. Biochemistry 2003; 42:7303-17. [PMID: 12809486 DOI: 10.1021/bi0342719] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure of the soluble Rieske protein from Thermus thermophilus has been determined at a resolution of 1.3 A at pH 8.5 using multiwavelength anomalous dispersion (MAD) techniques. This is the first report of a Rieske protein from a menaquinone-utilizing organism. The structure shows an overall fold similar to previously reported Rieske proteins. A novel feature of this crystal form appears to be a shared hydrogen between the His-134 imidazole ring ligated to Fe2 of the [2Fe-2S] cluster and its symmetry partner, His-134', one being formally an imidazolate anion, Fe2-(His-134)N(epsilon)(-)...H-N(epsilon')(His-134')-Fe2', in which crystallographic C(2) axes pass equidistant between N(epsilon)...N(epsilon') and normal to the line defined by N(epsilon)...N(epsilon'). This provides evidence for a stable, oxidized cluster with a His(-) ligand and lends support to a previously proposed mechanism of coupled proton and electron transfer. A detailed comparison of the Thermus Rieske protein with six other Rieske and Rieske-type proteins indicates: (a) The cluster binding domain is tightly conserved. (b) The 3-D structure of the 10 beta-strand fold is conserved, even among the most divergent proteins. (c) There is an approximately linear relation between acid-pH redox potential and number of H-bonds to the cluster. (d) These proteins have two faces, one points into the larger complex (bc(1), b(6)f, or other), is involved in the proton coupled electron transfer function, and is highly conserved. The second is oriented toward the solvent and shows wide variation in charge, sequence, length, hydrophobicity, and secondary elements in the loops that connect the beta-sheets.
Collapse
Affiliation(s)
- Laura M Hunsicker-Wang
- Division of Biology, the University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Yan J, Cramer WA. Functional insensitivity of the cytochrome b6f complex to structure changes in the hinge region of the Rieske iron-sulfur protein. J Biol Chem 2003; 278:20925-33. [PMID: 12672829 DOI: 10.1074/jbc.m212616200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Structure analysis of the cytochrome bc1 complex in the presence and absence of Qp quinol analog inhibitors implied that a large amplitude motion of the Rieske iron-sulfur protein (ISP) is required to mediate electron transfer from ubiquinol to cytochrome c1. Studies of the functional consequences of mutagenesis of an 8-residue ISP "hinge" region in the bc1 complex showed it to be sensitive to structure perturbation, implying that optimum flexibility and length are required for the large amplitude motion. Mutagenesis-function analysis carried out on the ISP hinge region of the cytochrome b6 f complex using the cyanobacterium Synechococcus sp. PCC 7002 showed the following. (i) Of three petC genes, only that in the petCA operon codes for functional ISP. (ii) The function of the complex was insensitive to changes in the hinge region that increased flexibility, decreased flexibility by substitutions of 4-6 Pro residues, shortened the hinge by a 1-residue deletion, or elongated it by insertion of 4 residues. The latter change increased sensitivity to Qp inhibitors, whereas deletion of 2 residues resulted in a loss of inhibitor sensitivity and a decrease in activity, indicating a minimum hinge length of 7 residues required for optimum binding of ISP at the Qp site. Thus, in contrast to the bc1 complex, the function of the b6 f complex was insensitive to sequence changes in the ISP hinge that altered its length or flexibility. This implies that either the barriers to motion or the amplitude of ISP motion required for function is smaller than in the bc1 complex.
Collapse
Affiliation(s)
- Jiusheng Yan
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-2054,USA
| | | |
Collapse
|
29
|
Abstract
The iron-sulfur protein subunit, known as the Rieske protein, is one of the central components of the cytochrome b(6)f complex residing in chloroplast and cyanobacterial thylakoid membranes. We have constructed plasmids for overexpression in Escherichia coli of full-length and truncated Rieske (PetC) proteins from the Spinacia oleracea fused to MalE. Overexpressed fusion proteins were predominantly found (from 55 to 70%) in cytoplasm in a soluble form. The single affinity chromatography step (amylose resine) was used to purify about 15mg of protein from 1 liter of E. coli culture. The isolated proteins were electrophoretically pure and could be used for further experiments. The NifS-like protein IscS from the cyanobacterium Synechocystis PCC 6803 mediates the incorporation of 2Fe-2S clusters into apoferredoxin and cyanobacterial Rieske apoprotein in vitro. Here, we used the recombinant IscS protein for the enzymatic reconstitution of the iron-sulfur cluster into full-length Rieske fusion and truncated Rieske fused proteins. Characterization by EPR spectroscopy of the reconstituted proteins demonstrated the presence of a 2Fe-2S cluster in both full-length and truncated Rieske fusion proteins.
Collapse
Affiliation(s)
- Beata Gubernator
- Institute of Biochemistry and Molecular Biology, Wrocław University, Tamka 2, 50-137 Wrocław, Poland
| | | | | | | |
Collapse
|
30
|
Wibom R, Hagenfeldt L, von Döbeln U. Measurement of ATP production and respiratory chain enzyme activities in mitochondria isolated from small muscle biopsy samples. Anal Biochem 2002; 311:139-51. [PMID: 12470673 DOI: 10.1016/s0003-2697(02)00424-4] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A set of methods suitable for assessment of respiratory chain function in mitochondria isolated from 25mg of muscle is described. This set of methods includes determination of the mitochondrial ATP production rate (MAPR) and the activities of the respiratory chain complexes I, I+III, II+III, and IV and citrate synthase. MAPR is determined with an optimized version of a luminometric method previously described. The optimized method measures 50-220% higher activities than the original method. The highest MAPRs are recorded using the substrate combinations glutamate+succinate and N,N,N(1),N(1)-tetramethyl-1,4-phenyldiamine+ascorbate. The respiratory chain complex activities are determined with standard spectrophotometric methods, adapted to an automated photometer. The sensitivity in the determination of complex I, I+III, and II+III activities was increased considerably by pretreating the samples with saponin. The set of methods was evaluated on double biopsy samples from five healthy volunteers and showed coefficients of variation between 7 and 14% when citrate synthase was used as reference base. All of the various measures of mitochondrial function showed high correlation coefficients to each other (r=0.84-0.98; p<0.01). It is concluded that the set of methods is suitable for diagnosis of mitochondrial disorders in adults and small children.
Collapse
Affiliation(s)
- Rolf Wibom
- Centre for Inherited Metabolic Diseases, Department of Medical Laboratory Sciences and Technology, Karolinska Institutet, Huddinge University Hospital, S-141 86 Stockholm, Sweden.
| | | | | |
Collapse
|
31
|
Cosper NJ, Eby DM, Kounosu A, Kurosawa N, Neidle EL, Kurtz DM, Iwasaki T, Scott RA. Redox-dependent structural changes in archaeal and bacterial Rieske-type [2Fe-2S] clusters. Protein Sci 2002; 11:2969-73. [PMID: 12441394 PMCID: PMC2373747 DOI: 10.1110/ps.0222402] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Proteins containing Rieske-type [2Fe-2S] clusters play important roles in many biological electron transfer reactions. Typically, [2Fe-2S] clusters are not directly involved in the catalytic transformation of substrate, but rather supply electrons to the active site. We report herein X-ray absorption spectroscopic (XAS) data that directly demonstrate an average increase in the iron-histidine bond length of at least 0.1 A upon reduction of two distantly related Rieske-type clusters in archaeal Rieske ferredoxin from Sulfolobus solfataricus strain P-1 and bacterial anthranilate dioxygenases from Acinetobacter sp. strain ADP1. This localized redox-dependent structural change may fine tune the protein-protein interaction (in the case of ARF) or the interdomain interaction (in AntDO) to facilitate rapid electron transfer between a lower potential Rieske-type cluster and its redox partners, thereby regulating overall oxygenase reactions in the cells.
Collapse
Affiliation(s)
- Nathaniel J Cosper
- Center for Metalloenzyme Studies, University of Georgia, Athens 30602, USA.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Gupta R, Mould RM, He Z, Luan S. A chloroplast FKBP interacts with and affects the accumulation of Rieske subunit of cytochrome bf complex. Proc Natl Acad Sci U S A 2002; 99:15806-11. [PMID: 12424338 PMCID: PMC137797 DOI: 10.1073/pnas.222550399] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Immunophilins are intracellular receptors of the immunosuppressants cyclosporin A, FK506, and rapamycin. Although all immunophilins possess peptidyl-prolyl isomerase activity and are identified from a wide range of organisms, little is known about their cellular functions. We report the characterization and functional analysis of an FK506 and rapamycin-binding protein (AtFKBP13) from Arabidopsis. The AtFKBP13 protein is synthesized as a precursor that is imported into chloroplasts and processed to the mature form located in the thylakoid lumen, as shown by chloroplast import assays and Western blot analysis. Experiments show that AtFKBP13 is translocated across the thylakoid membrane by the DeltapH-dependent pathway. Yeast two-hybrid screening identified Rieske FeS protein, a subunit of the cytochrome bf complex in the photosynthetic electron transport chain, as an interacting partner for AtFKBP13. Both yeast two-hybrid and in vitro protein-protein interaction assays showed that the precursor, but not the mature form, of AtFKBP13 interacted with Rieske protein, suggesting that interaction between the two proteins occurs along the import pathway. When AtFKBP13 expression was suppressed by RNA interference method, the level of Rieske protein was significantly increased in the transgenic plants.
Collapse
Affiliation(s)
- Rajeev Gupta
- Department of Plant and Microbial Biology, University of California, Berkeley 94720, USA
| | | | | | | |
Collapse
|
33
|
Zu Y, Fee JA, Hirst J. Breaking and re-forming the disulfide bond at the high-potential, respiratory-type Rieske [2Fe-2S] center of thermus thermophilus: characterization of the sulfhydryl state by protein-film voltammetry. Biochemistry 2002; 41:14054-65. [PMID: 12437363 DOI: 10.1021/bi026589r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A disulfide bond, adjacent to the [2Fe-2S] cluster, is conserved in all high-potential Rieske proteins from the respiratory and photosynthetic cytochrome bc(1) and b(6)f complexes but is absent from the low-potential, bacterial dioxygenase Rieske proteins. The role of the disulfide is unclear, since cysteine mutants have resulted in only apoprotein. The high stability of the soluble Thermus thermophilus Rieske protein permits chemical reduction of the disulfide bond and characterization of the sulfhydryl (dithiol) form by protein-film voltammetry. The effect of disulfide reduction on the cluster potential is small (DeltaE(0)' <or= -0.04 V) and attributed to relaxation of the disulfide tether between the protein loops ligating the cluster, including possible mechanical strain release and hydrogen-bonding modification. Above pH 6 an additional decrease in potential of the sulfhydryl form is assigned to the nearby negatively charged thiolates (DeltaE(0)' -0.16 to -0.12 V); the histidine-ligand nitrogen pKs are correspondingly increased. Entropies of reduction for the native and dithiolate forms are equal (-48 +/- 5 J K(-1) mol(-1), pH 7-8); thus changes in reduction potential are enthalpic in origin. Following sulfhydryl alkylation the cluster redox properties mirror those of the native protein (DeltaE(0)' approximately -0.1 V) over all pHs. While a sustained electrode potential of -0.85 V fails to reduce the disulfide, the free sulfhydryls recombine upon an oxidative excursion, at low pH, to restore the native redox properties. This unique behavior is attributed to preorganization of the two thiolate groups upon uptake of one or more protons by the sulfhydryl pair.
Collapse
Affiliation(s)
- Yanbing Zu
- Medical Research Council Dunn Human Nutrition Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 2XY, UK
| | | | | |
Collapse
|
34
|
Soriano GM, Guo LW, De Vitry C, Kallas T, Cramer WA. Electron transfer from the Rieske iron-sulfur protein (ISP) to cytochrome f in vitro. Is a guided trajectory of the ISP necessary for competent docking? J Biol Chem 2002; 277:41865-71. [PMID: 12207018 DOI: 10.1074/jbc.m205772200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The time course of electron transfer in vitro between soluble domains of the Rieske iron-sulfur protein (ISP) and cytochrome f subunits of the cytochrome b(6)f complex of oxygenic photosynthesis was measured by stopped-flow mixing. The domains were derived from Chlamydomonas reinhardtii and expressed in Escherichia coli. The expressed 142-residue soluble ISP apoprotein was reconstituted with the [2Fe-2S] cluster. The second-order rate constant, k(2)((ISP-f)) = 1.5 x 10(6) m(-1) s(-1), for ISP to cytochrome f electron transfer was <10(-2) of the rate constant at low ionic strength, k(2)((f-PC))(> 200 x 10(6) m(-1) s(-1)), for the reduction of plastocyanin by cytochrome f, and approximately 1/30 of k(2)((f-PC)) at the ionic strength estimated for the thylakoid interior. In contrast to k(2)((f-PC)), k(2)((ISP-f)) was independent of pH and ionic strength, implying no significant role of electrostatic interactions. Effective pK values of 6.2 and 8.3, respectively, of oxidized and reduced ISP were derived from the pH dependence of the amplitude of cytochrome f reduction. The first-order rate constant, k(1)((ISP-f)), predicted from k(2)((ISP-f)) is approximately 10 and approximately 150 times smaller than the millisecond and microsecond phases of cytochrome f reduction observed in vivo. It is proposed that in the absence of electrostatic guidance, a productive docking geometry for fast electron transfer is imposed by the guided trajectory of the ISP extrinsic domain. The requirement of a specific electrically neutral docking configuration for ISP electron transfer is consistent with structure data for the related cytochrome bc(1) complex.
Collapse
Affiliation(s)
- Glenda M Soriano
- Department of Biological Sciences and Program in Biochemistry/Molecular Biology, Purdue University, West Lafayette, Indiana 47907-1392, USA
| | | | | | | | | |
Collapse
|
35
|
Abstract
GRACILE syndrome (Fellman syndrome, MIM 603358), an autosomal recessive metabolic disorder of the Finnish disease heritage, has been diagnosed in 25 infants of 18 families. The incidence is at least 1/47,000 in Finland. The main findings are fetal growth retardation, Fanconi type aminoaciduria, cholestasis, iron overload (liver hemosiderosis, hyperferritinemia, hypotransferrinemia, increased transferrin iron saturation, and free plasma iron), profound lactic acidosis, and early death. The pathophysiology of the metabolic disturbance is unsolved. No significant deficiency of complex III activity of respiratory chain has been found, although we recently showed that the underlying genetic cause is a missense mutation (S78G) in the BCS1L gene and other mutations in that gene have been associated with complex III deficiency. BCS1L encodes a mitochondrial protein, acting as a chaperone in the assembly of complex III. Iron accumulation in liver, a typical feature being less abundant with increasing age, might be a primary abnormality or a secondary phenomenon due to liver dysfunction. In order to decrease the iron overload, three infants have been repeatedly treated with apotransferrin followed by exchange transfusion. Improvement in iron biochemistry occurred, but no clear beneficial effect on the clinical condition was found. Further studies will elucidate the role of iron in the pathophysiology of the disease.
Collapse
Affiliation(s)
- Vineta Fellman
- Hospital for Children and Adolescents, University of Helsinki, Stenbäcksgatan 22, Helsinki PB 281, Finland.
| |
Collapse
|
36
|
Abstract
The first crystal structure of an archaeal Rieske iron-sulfur protein, the soluble domain of Rieske iron-sulfur protein II (soxF) from the hyperthermo-acidophile Sulfolobus acidocaldarius, has been solved by multiple wavelength anomalous dispersion (MAD) and has been refined to 1.1 A resolution. SoxF is a subunit of the terminal oxidase supercomplex SoxM in the plasma membrane of S. acidocaldarius that combines features of a cytochrome bc(1) complex and a cytochrome c oxidase. The [2Fe-2S] cluster of soxF is most likely the primary electron acceptor during the oxidation of caldariella quinone by the cytochrome a(587)/Rieske subcomplex. The geometry of the [2Fe-2S] cluster and the structure of the cluster-binding site are almost identical in soxF and the Rieske proteins from eucaryal cytochrome bc(1) and b(6)f complexes, suggesting a strict conservation of the catalytic mechanism. The main domain of soxF and part of the cluster-binding domain, though structurally related, show a significantly divergent structure with respect to topology, non-covalent interactions and surface charges. The divergent structure of soxF reflects a different topology of the soxM complex compared to eucaryal bc complexes and the adaptation of the protein to the extreme ambient conditions on the outer membrane surface of a hyperthermo-acidophilic organism.
Collapse
Affiliation(s)
- Heiko Bönisch
- Department of Biosciences at NOVUM, Center for Structural Biochemistry, Karolinska Institutet, Hälsovägen 7-9, S-14157 Huddinge, Sweden
| | | | | | | |
Collapse
|
37
|
Ullmann GM, Noodleman L, Case DA. Density functional calculation of p K(a) values and redox potentials in the bovine Rieske iron-sulfur protein. J Biol Inorg Chem 2002; 7:632-9. [PMID: 12072969 DOI: 10.1007/s00775-002-0342-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2001] [Accepted: 12/19/2001] [Indexed: 10/27/2022]
Abstract
The redox potential of the Rieske iron-sulfur protein depends on pH. It has been proposed that the histidines coordinating one of the irons are responsible for this pH dependence, but an experimental proof for this proposal is still lacking. In this work, we present a density functional/continuum electrostatics calculation of the p K(a) values of the histidines in the Rieske iron-sulfur center. The calculated apparent p K(a) values are 6.9 and 8.8 in the oxidized state, which are in good agreement with the corresponding experimental values of 7.5 and 9.2 and the measured pH dependence of the redox potential. Neither of these two p K(a) values can, however, be assigned to only one of the histidines. We find that both histidines titrate over a wide pH range in the oxidized state. Reduction of the iron-sulfur center shifts the p K(a) values to 11.3 and 12.8, thus above 10.0 as found experimentally. The results provide a complete picture of the coupling of proton and electron binding, showing strongly cooperative binding of protons at electrode potentials near the redox midpoint potential of the cluster. The potential biological function of the low p K(a) value of the histidines and the shift upon reduction are briefly discussed.
Collapse
Affiliation(s)
- G Matthias Ullmann
- Department of Moleular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | |
Collapse
|
38
|
Jahns P, Graf M, Munekage Y, Shikanai T. Single point mutation in the Rieske iron-sulfur subunit of cytochrome b6/f leads to an altered pH dependence of plastoquinol oxidation in Arabidopsis. FEBS Lett 2002; 519:99-102. [PMID: 12023025 DOI: 10.1016/s0014-5793(02)02719-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The pgr1 mutant of Arabidopsis thaliana carries a single point mutation (P194L) in the Rieske subunit of the cytochrome b6/f (cyt b6/f) complex and is characterised by a reduced electron transport activity at saturating light intensities in vivo. We have investigated the electron transport in this mutant under in vitro conditions. Measurements of P700 reduction kinetics and of photosynthetic electron transport rates indicated that electron transfer from cyt b6/f to photosystem I is not generally reduced in the mutant, but that the pH dependence of this reaction is altered. The data imply that the pH-dependent inactivation of electron transport through cyt b6/f is shifted by about 1 pH unit to more alkaline pH values in pgr1 thylakoids in comparison with wild-type thylakoids. This interpretation was confirmed by determination of the transmembrane deltapH at different stromal pH values showing that the lumen pH in pgr1 mutant plants cannot drop below pH 6 reflecting most likely a shift of the pK and/or the redox potential of the oxidised Rieske protein.
Collapse
Affiliation(s)
- Peter Jahns
- Plant Biochemistry, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, Düsseldorf, Germany.
| | | | | | | |
Collapse
|
39
|
Knight JS, Duckett CM, Sullivan JA, Walker AR, Gray JC. Tissue-specific, light-regulated and plastid-regulated expression of the single-copy nuclear gene encoding the chloroplast Rieske FeS protein of Arabidopsis thaliana. Plant Cell Physiol 2002; 43:522-31. [PMID: 12040099 DOI: 10.1093/pcp/pcf062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The single-copy PetC gene encoding the chloroplast Rieske FeS protein of Arabidopsis thaliana consists of five exons interrupted by four introns and encodes a protein of 229 amino acid residues with extensive sequence similarity to the chloroplast Rieske proteins of other higher plants. The N-terminal 50 amino acid residues constitute a presequence for targeting to the chloroplast and the remaining 179 amino acid residues make up the mature protein. Three of the introns are in identical positions in the PetC gene of Chlamydomonas reinhardtii, suggesting that they are of ancient origin. RNA-blot hybridisation showed that the gene was expressed in shoots, but not roots, and was light regulated and repressed by sucrose. The expression of chimeric genes consisting of PetC promoter fragments fused to the beta-glucuronidase (GUS) reporter gene was examined in A. thaliana and tobacco. In A. thaliana, GUS activity was detected in leaves, stems, flowers and siliques, but not in roots, and showed a strong correlation with the presence of chloroplasts. In transgenic tobacco, low levels of GUS activity were also detected in light-exposed roots. GUS activity in transgenic tobacco seedlings was light regulated and was decreased by norflurazon in the light suggesting regulation of PetC expression by plastid signals.
Collapse
Affiliation(s)
- Julie S Knight
- Department of Plant Sciences and Cambridge Centre for Molecular Recognition, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | | | | | | | | |
Collapse
|
40
|
Staniek K, Gille L, Kozlov AV, Nohl H. Mitochondrial superoxide radical formation is controlled by electron bifurcation to the high and low potential pathways. Free Radic Res 2002; 36:381-7. [PMID: 12069101 DOI: 10.1080/10715760290021225] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The generation of oxygen radicals in biological systems and their sites of intracellular release have been subject of numerous studies in the last decades. Based on these studies mitochondria are considered to be the major source of intracellular oxygen radicals. Although this finding is more or less accepted, the mechanism of univalent oxygen reduction in mitochondria is still obscure. One of the most critical electron transfer steps in the respiratory chain is the electron bifurcation at the cytochrome bc1 complex. Recent studies with genetically mutated mitochondria have made it clear that electron bifurcation from ubiquinol to the cytochrome bc1 complex requires the free mobility of the head domain of the Rieske iron-sulfur protein. On the other hand, it has been long known that inhibition of electron bifurcation by antimycin A causes leakage of single electrons to dioxygen, which results in the release of superoxide radicals. These findings lead us to study whether hindrance of the interaction of ubiquinol with the cytochrome bc1 complex is the regulator of single electron diversion to oxygen. Hindrance of electron bifurcation was observed following alterations of the physical state of membrane phospholipids in which the cytochrome bc1 complex is inserted. Irrespective of whether the fluidity of the membrane lipids was elevated or decreased, electron flow rates to the Rieske iron-sulfur protein were drastically reduced. Concomitantly superoxide radicals were released from these mitochondria, strongly suggesting an effect on the mobility of the head domain of the Rieske iron-sulfur protein. This revealed the involvement of the ubiquinol cytochrome bc1 redox couple in mitochondrial superoxide formation. The regulator, which controls leakage of electrons to oxygen, appears to be the electron-branching activity of the cytochrome bc1 complex.
Collapse
Affiliation(s)
- Katrin Staniek
- Institute of Pharmacology and Toxicology, Veterinary University Vienna, Austria
| | | | | | | |
Collapse
|
41
|
Schneider D, Skrzypczak S, Anemüller S, Schmidt CL, Seidler A, Rögner M. Heterogeneous Rieske proteins in the cytochrome b6f complex of Synechocystis PCC6803? J Biol Chem 2002; 277:10949-54. [PMID: 11788579 DOI: 10.1074/jbc.m104076200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The completely sequenced genome of the cyanobacterium Synechocystis PCC6803 contains three open reading frames, petC1, petC2, and petC3, encoding putative Rieske iron-sulfur proteins. After heterologous overexpression, all three gene products have been characterized and shown to be Rieske proteins as typified by sequence analysis and EPR spectroscopy. Two of the overproduced proteins contained already incorporated iron-sulfur clusters, whereas the third one formed unstable aggregates, in which the FeS cluster had to be reconstituted after refolding of the denatured protein. Although EPR spectroscopy showed typical FeS signals for all Rieske proteins, an unusual low midpoint potential was revealed for PetC3 by EPR redox titration. Detailed characterization of Synechocystis membranes indicated that all three Rieske proteins are expressed under physiological conditions. Both for PetC1 and PetC3 the association with the thylakoid membrane was shown, and both could be identified, although in different amounts, in the isolated cytochrome b(6)f complex. The considerably lower redox potential determined for PetC3 indicates heterogeneous cytochrome b(6)f complexes in Synechocystis and suggests still to be established alternative electron transport routes.
Collapse
Affiliation(s)
- Dirk Schneider
- Lehrstuhl für Biochemie der Pflanzen, Fakultät für Biologie, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | | | | | | | | | | |
Collapse
|
42
|
Abstract
Many current models of the Q cycle for the cytochrome (cyt) b6f and the cyt bc1 complexes incorporate 'Rieske' iron-sulfur protein (ISP) domain movements to gate electron transfer and to ensure high yields of proton shuttling. It was previously proposed that copper ions, which bind at a site distant from the quinol oxidase (Q(o)) site, inhibit plastoquinol (PQH2) binding by restraining the hydrophilic head domain of the ISP [Rao B. K., S., Tyryshkin, A. M., Roberts, A. G., Bowman, M. K., and Kramer, D. M. (1999) Biochemistry 38, 3285-3296]. The present work presents evidence that this is indeed the case for both copper ions and Zn2+, which appear to inhibit by similar mechanisms. Electron paramagnetic resonance (EPR) spectra show that Cu2+ and Zn2+ binding to the cyt b6f complex displaces the Q(o) site inhibitor 2,5-dibromo-3-methyl-6-isopropylbenzoquinone (DBMIB). At high concentrations, both DBMIB and Cu2+ or Zn2+ can bind simultaneously, altering the Rieske 2Fe2S cluster and Cu2+ EPR spectra, suggesting perturbations in their respective binding sites. Both Zn2+ and Cu1+ altered the orientations of the Rieske 2Fe2S cluster with respect to the membrane plane, but had no effect on that of the cyt b6 hemes. Cu2+ was found to change the orientation of the cyt f heme plane, consistent with binding on the cyt f protein. Within conservative constraints, the data suggest that the ISP is shifted into a position intermediate between the ISP(C) position, when the Q(o) site is unoccupied, and the ISP(B) position, when the Q(o) site is occupied by inhibitors such as DBMIB or stigmatellin. These results support the role of ISP domain movements in Q(o) site catalysis.
Collapse
Affiliation(s)
- Arthur G Roberts
- Institute of Biological Chemistry, Washington State University, 289 Clark Hall, Pullman, Washington 99164-6340, USA
| | | | | |
Collapse
|
43
|
Baxter NJ, Scanlan J, De Marco P, Wood AP, Murrell JC. Duplicate copies of genes encoding methanesulfonate monooxygenase in Marinosulfonomonas methylotropha strain TR3 and detection of methanesulfonate utilizers in the environment. Appl Environ Microbiol 2002; 68:289-96. [PMID: 11772638 PMCID: PMC126542 DOI: 10.1128/aem.68.1.289-296.2002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Marinosulfonomonas methylotropha strain TR3 is a marine methylotroph that uses methanesulfonic acid (MSA) as a sole carbon and energy source. The genes from M. methylotropha strain TR3 encoding methanesulfonate monooxygenase, the enzyme responsible for the initial oxidation of MSA to formaldehyde and sulfite, were cloned and sequenced. They were located on two gene clusters on the chromosome of this bacterium. A 5.0-kbp HindIII fragment contained msmA, msmB, and msmC, encoding the large and small subunits of the hydroxylase component and the ferredoxin component, respectively, of the methanesulfonate monooxygenase, while a 6.5-kbp HindIII fragment contained duplicate copies of msmA and msmB, as well as msmD, encoding the reductase component of methanesulfonate. Both sets of msmA and msmB genes were virtually identical, and the derived msmA and msmB sequences of M. methylotropha strain TR3, compared with the corresponding hydroxylase from the terrestrial MSA utilizer Methylosulfonomonas methylovora strain M2 were found to be 82 and 69% identical. The msmA gene was investigated as a functional gene probe for detection of MSA-utilizing bacteria. PCR primers spanning a region of msmA which encoded a unique Rieske [2Fe-2S] binding region were designed. These primers were used to amplify the corresponding msmA genes from newly isolated Hyphomicrobium, Methylobacterium, and Pedomicrobium species that utilized MSA, from MSA enrichment cultures, and from DNA samples extracted directly from the environment. The high degree of identity of these msmA gene fragments, compared to msmA sequences from extant MSA utilizers, indicated the effectiveness of these PCR primers in molecular microbial ecology.
Collapse
Affiliation(s)
- Nardia J Baxter
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | | | | | | | | |
Collapse
|
44
|
Molik S, Karnauchov I, Weidlich C, Herrmann RG, Klösgen RB. The Rieske Fe/S protein of the cytochrome b6/f complex in chloroplasts: missing link in the evolution of protein transport pathways in chloroplasts? J Biol Chem 2001; 276:42761-6. [PMID: 11526115 DOI: 10.1074/jbc.m106690200] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Rieske Fe/S protein, a nuclear-encoded subunit of the cytochrome b(6)/f complex in chloroplasts, is retarded in the stromal space after import into the chloroplast and only slowly translocated further into the thylakoid membrane system. As shown by the sensitivity to nigericin and to specific competitor proteins, thylakoid transport takes place by the DeltapH-dependent TAT pathway. The Rieske protein is an untypical TAT substrate, however. It is only the second integral membrane protein shown to utilize this pathway, and it is the first authentic substrate without a cleavable signal peptide. Transport is instead mediated by the NH(2)-terminal membrane anchor, which lacks, however, the twin-arginine motif indicative of DeltapH/TAT-dependent transport signals. Furthermore, transport is affected by sodium azide as well as by competitor proteins for the Sec pathway in chloroplasts, demonstrating for the first time some cross-talk of the two pathways. This might take place in the stroma where the Rieske protein accumulates after import in several complexes of high molecular mass, among which the cpn60 complex is the most prominent. These untypical features suggest that the Rieske protein represents an intermediate or early state in the evolution of the thylakoidal protein transport pathways.
Collapse
Affiliation(s)
- S Molik
- Institut für Pflanzenphysiologie, Martin-Luther-Universität Halle-Wittenberg, Weinbergweg 10, D-06120 Halle (Saale), Germany
| | | | | | | | | |
Collapse
|
45
|
Zu Y, Fee JA, Hirst J. Complete thermodynamic characterization of reduction and protonation of the bc(1)-type Rieske [2Fe-2S] center of Thermus thermophilus. J Am Chem Soc 2001; 123:9906-7. [PMID: 11583559 DOI: 10.1021/ja016532c] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Y Zu
- Medical Research Council, Dunn Human Nutrition Unit, Hills Road Cambridge, CB2 2XY, U.K
| | | | | |
Collapse
|
46
|
Luo W, Moe LA, Skjeldal L, Pikus JD, Markley JL, Fox BG. Assignment of 1H, 13C and 15N NMR signals from toluene 4-monooxygenase Rieske ferredoxin in its oxidized state. J Biomol NMR 2001; 21:73-74. [PMID: 11693573 DOI: 10.1023/a:1011924200884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
47
|
Costas M, Tipton AK, Chen K, Jo DH, Que L. Modeling Rieske dioxygenases: the first example of iron-catalyzed asymmetric cis-dihydroxylation of olefins. J Am Chem Soc 2001; 123:6722-3. [PMID: 11439071 DOI: 10.1021/ja015601k] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
48
|
Affiliation(s)
- G Schäfer
- Institute of Biochemistry, Medical University of Lübeck, Lübeck D-23538, Germany
| | | | | |
Collapse
|
49
|
Rabilloud T, Strub JM, Luche S, van Dorsselaer A, Lunardi J. A comparison between Sypro Ruby and ruthenium II tris (bathophenanthroline disulfonate) as fluorescent stains for protein detection in gels. Proteomics 2001; 1:699-704. [PMID: 11678039 DOI: 10.1002/1615-9861(200104)1:5<699::aid-prot699>3.0.co;2-c] [Citation(s) in RCA: 233] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A comparison between two fluorescent metal chelates for staining proteins separated by electrophoresis has been carried out. One of these chelates is ruthenium II tris (bathophenanthroline disulfonate) and the other is commercial Sypro Ruby. Both can be efficiently detected either with UV tables or with commercial laser fluorescence scanners. The sensitivity and homogeneity of the stains and the interference with mass spectrometry analysis have been investigated. It appears that both stains perform similarly for protein detection, while ruthenium II tris (bathophenanthroline disulfonate) performs better for mass spectrometry analyses and as cost-effectiveness ratio. However, Sypro Ruby is easier to use as a stain.
Collapse
Affiliation(s)
- T Rabilloud
- CEA-Laboratoire de Bioénergétique Cellulaire et Pathologique, DBMS/BECP CEA-Grenoble, Grenoble, France.
| | | | | | | | | |
Collapse
|
50
|
Ahmed FA, Jequier AM, Cummins JM, Whelan J. Differentially expressed DNA sequences following recovery from unilateral testicular torsion in rat. Biochim Biophys Acta 2001; 1535:192-9. [PMID: 11342008 DOI: 10.1016/s0925-4439(00)00099-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The molecular response during recovery from torsion-induced stress in the testis is diverse with a variety of mechanisms. In this study, using unilateral testicular torsion in rat as a model, we used subtractive hybridisation to identify differentially expressed DNA sequences in the torsioned and control testes. Three genes were identified as being down regulated in the torsioned testis compared with controls: Control Testis genes 1, 2 and 3 (CT1, CT2 and CT3). Two genes were up regulated in the torsioned testes: Torsioned Testes genes 1 and 2 (TT1 and TT2). Differential expression was confirmed by Reverse Northern blot analysis. An homology search revealed that CT1 had 88% homology with rat metallothionein cDNA; CT2 had 81% homology with rat cell surface antigen in MHC class I, but no homology could be found for CT3. TT1 had 92% identity with rat Rieske iron-sulphur protein mRNA whereas TT2 had 73% identity with a human clone of unknown function (RP 11-252D22). These results indicate that changes in gene expression occur following torsion induced stress, and that identification of differentially expressed genes may provide insights into the mechanisms of cellular tissue damage in this model.
Collapse
Affiliation(s)
- F A Ahmed
- Department of Biochemistry, University of Western Australia, Nedlands
| | | | | | | |
Collapse
|